Leather stretching machine



June 2, 1 931. J. H. HARRISON V I LEATHER STRETCHING MACHINE 3 Sheets-Shet 1 Filed Jan. 31. 1929 June 2, 1931. J. H. HARRISON LEATHER STRETCHING MACHINE Filed Jan. 31. 1929 3 Sheets-Sheet 2 June 2, 1931. J. H. HARRISON LEATHER STRETCHING mcams Filed Jan. 51, 1929 SSheetS-Sheet 3 a II a 9 5 Patented June 2, 1931 UNITED STATES PATENT OFFICE JOSEPH H. HARRISON, OF GOMERSALL, NEAR LEEDS, ENGLAND, ASSIGNOR T0 TURNER TANNING MACHINERY COMPANY, OF PORTLAND, MAINE, A CORPORATION OF. MAINE LEATHER STBETCHING MACHINE Application filed January 31, 1929,"S'eria1Nn. 336,607, and in Great Britain February 14,1928.

is tinguished from putting out and setting machines wherein stretching of the-work is more or less incidental to the other operations, and as distinguished from frames for stretching pieces of leather and maintaining them in stretched conditi0n,no provision was made,

its-heretofore constructed, for preventingthe drawing in of the side edges of the leather during stretching operations. In other words, no means was provided for maintain- 59 ing, asvnearly as possible, the normal Width of the piece of leather while it was being stretched in a direction at right angles to its transverse dimension, it being a well known fact that when a piece of leather-is stretched along lines joining opposite edgesthereof it tends to narrow or draw :in along lines extending at right angles to the first-mentioned lines. Hence, pieces of work stretched in the machines of old and well-known constructions were frequently so distorted in shape that portions of the side edges had to be trimmed away in order to secure pieces of leather of uniform width. Another defect or deficiency in such prior machines was found in the amount of time consumed in attaching a piece of work temporarily .to a means for p-ulling'the work through-or past the stretching means, the result being that the capacity of such machines wasgreatly restricted.

Objects of this invention are to produce work of a higher quality than that heretofore possible while at the same time increasing production, and to secure a product in which no trimmin 'of the work is necessar due to narrowing o-f-the work during thestretching operations.

To these ends, and in accordance with an important feature of the invention, there is provided, in the illustrated leather stretcha means.

preferably controllable through a manually operable lever so that th'e operator-may initiate rolling of'apiece of work in a roll'along;

ing machine, improved means formaint-aining approximately the normal width of-the "piece of worlvduring stretching operations. Preferably, and asshown, the means for maintainingthe width of the work comprises a spreading roll which serves also as 'oneof the members which co-operate'witha stretching bladein stretching operations upon the work. Since'the "Workisspread in a lateral direction while it is'under tension in :the dis rection of the stretching operations, it is prevented from contracting or narrowing disadvantageously in its transverse dimension while beingstretched along lines more or less at right anglesto the said transverse dimension.

It-is also an important feature of the :lll WQlb tion that means is provided for readily attaching a piece of work temporarily to a member which pulls portions of the workthrough or past the stretching means. Conveniently, this attachingmeans comprises an apron adapted to contact with a portion of the work and to be rolled therewith upon a roll member which rotates to pull'otherportions of the work through the stretching While the-rotatable roll member is with the apron, means is preferably provided for automatically terminating the rolling op eration when the stretching means becomes inoperative. As shown, a hand-operated lever is utilized to initiate power operation. of

theroll member and connections areprovided to the power means WlllCl'l operates the stretchlng means to cause disconnection of power from the roll member while the stretching means isbelng rendered moper-P ative.

These and other features of the invention and novel combinations of parts will now'be described in detail and thenpointed out more particularly in the appended claims.

Figure 1 is a sectional end elevation of a 'machine illustrating one embodiment of the invention;

Fig. 9.,is an end elevation ofthe machine illustrated in Fig. 1.;

Fig. 3 is a front elevation of the machine illustrated in Figs. 1 and 2;

Fig. 4c is a sectional plan on line IV-IV of Fig. 2;

Fig. 5 shows the work spreading member per se;

Fig. 6 is a sectional detail of the work spreading member;

Fig. 7 is an end view of automatic stopping means for the draw roller;

Fig. 8 is a side view of the stopping means;

Fig. 9 is a sectional plan view of such means; and

Fig. 10 illustrates the controlling cam employed in the stopping means.

In the illustrated machine, which is especially constructed for the stretching of pieces of leather, a cylindrical work support 1, formed with alternately arranged spiral grooves and ribs 1a. 15, (see Figs. 5 and 6) and a plain cylindrical work support 2, are respectively mounted in parallel jaws 3 and 4 (Fig. 1). Left and right hand grooves and ribs of approximately pitch extending from a point intermediate of the ends of the support 1, as represented in Fig. 5. and of the form shown on an enlarged scale in Fig. 6, make of the support- 1 a. leather stretching member as will be hereinafter described. The jaw 3 is fixed and the jaw 1- is adapted to rock in the machine frame 5, for which purpose said aw rests on an arcuate formation 4a (see Fig. 1), which constitutes a fulcrum for the jaw. Each of the work supports 1 and 2 is provided at or near its opposite ends with six equidistant radial tapped holes 6 and is fixed in the aw therefor, at each end, by means of a screw 7 inserted through the jaw and into one of said holes. By withdrawing the screws 7 the support 1 or 2 may be rotated in the aw to bring other holes into register with the screws and consequently a fresh portion of each support may be thus brought into use when wear has taken place, the supports being. of course, rigidly locked in position when the screws are reinserted. The jaws 3 and 4 are connected by non-rotatable screws 8, which pass through clearance holes 9 suitably spaced in the aws and are surrounded by compression springs 10 interposed between the jaws. worm wheels 11 being threaded on said screws. as shown in Fig. 1. The screws 8 are each held from rotation by a peg 12 therein which engages a corresponding recess or keyway in the movable jaw 45. Heads 8a of the screws 8 on the one hand and the worm wheels 11 on the other hand offer positive resistance to separation of the jaws during the stretching action, but by rotating the worm wheels 11 so that the screws move endwise therethrough, the rocking jaw 4; can be adjusted in relation to the fixed jaw 3. The springs 10 move or hold the rocking jaw away from the fixed jaw, while the screws 8 effect the reverse movement. In this manner the distance between the two cylindrical supports 1 and 2 can be varied, the arrangement allowing for sufficient ad ustment to suit different thicknesses of work. Set screws 13 are provided in the lower end of the fixed aw 3, as shown in Fig. 1 to avoid undesirable tilting of the rocking jaw, more particularly when the support 2 is brought closer to the stretching member so as to enable the machine to deal with comparatively thin work.

The worm wheels 11 mesh with worms 14 (Figs. 1 and 3) on a common shaft 15 rotatable in bearings 16 carried by the fixed jaw 3 and operable by a hand wheel 17 at one end of the machine.

The supports 1 and 2 are disposed on op posite sides of a blade member 18 (Figs. 1, 2 and 3) fixed on a reciprocatory beam 19 by clamp plates 20 and screws 21. Provision is made in an old and well-known manner (not disclosed) for adjusting said blade vertically on the beam according to requirements. The beam 19 is movable up and down in the machine frame 5 so as to carry the blade men'r ber 18 edgewise into and out of the space between the supports 1 and 2, and for this purpose the beam is furnished at opposite ends with slide blocks 23 (Figs. 2 and 3) which work between opposing vertical guides 2i formed in or on the machine frame. Said blocks 23 have attached thereto rods 25 connected respectively to a crank 26, and to a crank pin 26a in a gear (hereinafter referred to), both on a power driven shaft 27. This shaft is driven through the medium of a clutch 28 on a primary shaft 29 by means of a pinion 30 (Figs. 2, 3 and on shaft 25) and a. gear Wheel 31 on shaft 27. The clutch 28 is operated from a treadle 3% through a. link to an arm 36 on a rock shaft 33. Fastencd to shaft 33 is a forked arm 32 for directly operating the clutch 28. The clutch 28 (and coneequentl the rotation of the shaft 27) is controlled by a half cycle mechanism of a well-knovm form, whereby the clutch shaft is stopped with the blade member either in the operative or inoperative position, will now be described. The illustrated mechanism comprises a disc 37 fixed on the shaft 27 and formed with two diametrically opposed notches or recesses 3764 (Fig. 2) and an arm 38 mounted on treadle shaft 39 and held in engagement with the disc by a spring 38a 3) connected to the treadle so as to cause said arm to enter one or the other of the notches or recesses at each half cyc.e of the shaft 27, and thus throw out the clutch and at the same time hold the shaft 2'? and parts connected thereto in one or the other of two resting positions. When the shaft 2? is held. locked in the position shown in Fig. .2, the blade 18 is held down between the mem bers 1 and 2, as indicated in Figs. 1 and E2, in operative position. When the shaft 27 is rotated through a half revolution and then locked by member EBB-and the other notch 37a, the blade is held in its upper position of rest so that a piece of work may bereadily introduced.

vVhile a draw roller 10 of any convenient form may be employed to pull the work 41 along between the blade member 18 and the supports 1 and 2, it is preferred to employ one furnished with a longitudinal groove or channel 12 1) and a leather apron 43 having one end 43a clamped in the groove or channel by a clamp plate 4% and fixing screws 45. This roller 10is mounted on a shaft =16 located on the same side of the blade member 18 as the spirallygrooved support 1, as illustrated in Fig. 1. Referring to Figs. 2, 3 and at, the roller shaft 4.6 is preferably gear driven from a counter shaft 1? which is driven in its turn by suitable means such as a chain drive 18, 19, (see Fig. from the primary shaft 29. The gearing for driving the draw roller shaft also includes a pinion 51 slidable on the counter shaft 47 for movement into and out of mesh with a gear 52 on the roller shaft 46. The pinion 51 may be moved into and out of mesh with the gear 52 by a handle 53 and a striking fork 5 1 on a vertical rock shaft 55. Normally the pinion 51 is out of mesh with the gear 52. Preferably and as shown, the pinion 51 is moved into mesh with the gear 52 by means of the aforesaid handle and associated parts, and mechanism is provided which functions automatically to disconnect the pinion and gear to render the draw roller 16 inoperative upon the upward movement ofthe blademember 18 from between the aforesaid supports 1 and 2. A practical example of such means is illustrated in Figs. 7 to 10, inclusive, and comprises a snail-shaped cam 56 carried by a spindle 57 rotatable in .a bearing 58 mounted on carrier bars 58a fixed in the. machine frame. The spindle 57 is connected to the crank pin 2664 by an arm 59. The cam 56 engages a roller 60 carried by a lever 61 fulcrumed at 62 on the bearing 58, which lever, at its upper end, carries a link 63 pivotally connected to an arm 64 on the aforesaid verti The rotation of the draw cal rock shaft 55. roller is started by thehandle 53, the aforesaid connections then being in the position shown in Figs. 7, 8 and 9, but when the treadle 3. is operated to initiate upward movement of the blade member 18 after the stretching operation, the cam 56 rotates through half a revolution inthe direction of the arrow in Fig. 7 into the position shown in Fig. 10, thereby actuating the lever 61 and moving the shaft 55, so that the pinion 51 is drawn out of mesh with the gear 52, whereupon the rotation of the draw roller 40 ceases, As shown in Fig. 10, the cam 56 stops in a position clear of'the lever 61 so as not to interfere with subsequent movement of the draw roller pinion 51 into operative position by the hand operated parts 53, 55.

In the operation of the aforesaid machine, approximately one-half of the work is thrown over both thecylindrical supports 1 and 2 while the blade member 18 is raised, and then the leather apron 13 on the draw roller 10 is laid upon the adjacent end of the other half of the work. The draw roller is first started by means of the handle 53 so that both the apron and a portion of the work are initially rolled or wrapped around the roller, whereby the work is tightly gripped. When the operator observes that a portion of the work and the apron have been wound upon the roll 40 to grip the work, the treadle 34: is then promptly actu ated so that the blade member 18 descends edgewise between the supports 1 and 2 and forces the work into the space between the supports as represented in Fig. 1, with a wedging action. The supports 1 and 2 offer an adjustably predetermined resistance to this action as already explained herein. Considerable resistance is thus also offered by the supports 1 and 2 in cooperation with the blade 18 to the pull of the draw roller 40 upon the piece of work whereby the work is correspondingly tensioned and stretched during the further rotation of the draw roller. Since the draw roller is disposed somewhat below the level of the grooved support 1, and since the blade 18 folds the work over a considerable portion of the surface of the Support 1, the work is drawn round the support and is subjected to the spreading action of the grooves 1a and ribs 15 therein. First one half of the work is treated in this manner, and the machine is stopped. Subsequently the work is unwound from the draw roller 40 and reversed and the operation repeated on the other half.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. 1 In a machine for stretching hides, skins, leather and other similar pieces of work, means comprising two members having curved surfaces and a member having an edged surface for releasably engaging opposite surfaces of a piece of work, means for moving the piece of work past the workengaging members to effect stretching operations thereon, and means comprising a spreader surface on one of the two first-mentioned members for spreauing the work in a direction transverse to the direction of -movement of the work so as to maintain approximately the normal width of the piece of work during stretching thereof.

.2. In a machine for stretching hides, skins, leather and other similar pieces of work, two members spaced from each other and having curved surfaces to engage frictionally witn a piece of work, a blade over the edge of which the work is folded upon relative movement between the blade and the members, means moving the piece 01 work past the members and the blade in a direction at a right angle thereto to ellect stretching of the work, and means for spreading the work in a direction transverse to its direction or" movement past the members so that the work is spread laterally at the same time that it is being stretch-ed.

S. In a machine for stretching hides, skins, leather and other similar pieces of work, a pair of work engaging members spaced from each other, a blade arranged in a. plane be tween and parallel to the work engaging members, means for causing relative movement between the work engaging members on one side of the work and the blade on the other side to told the work around the edge of the blade, means for pulling the work past the edge of the blade, and means located on the surface of one of the work en members for spreading the work in a direction transverse to its direction of movement so as to maintain approximately the normal width of the piece of work while it is being stretched.

l. In a machine for stretching hides, skins, leather and other similar pieces of work, power means for stretching a piece of work along lines joining opposite edges thereof. said, means comprising two members having cylindrical surfaces and a bladed men'ibcr located between said surfaces, and means operative simultaneously with he first-n'lentioned means and controlled thereby for spreading the piece of work in directions at right angles to the first-mentioned lines so as to maintain approximately the normal width of the piece of work during stretching hereof. the spreading means comprising a spreader surface on one of the cylindrical surfaces of the stretching members.

In machine for stretching hides, skins, leather and other similar pieces of work, a support for a piece of wor; comprising two closely spaced members, a blade arranged to project into the space between the two members to cause the work to folded sha ply around the blade, means for pulling the work past the blade to etlect stretching thereof, and means comprising a stationary helicallv bladed member for spreading the work in a direction transverse to the direction of stretch of the work as to maintain approxin'iately the normal dth olthe piece of work durin stretchin thereof.

6. In a. machine for stretching hides, skins, leather and other similar pieces ot work, a pair of stationary members closely space L with respect to each other and arranged to serve as a rmrk support, a bladed member, means for moving the bladec. member to fol d the work in between the two work supporting members and around the edge of the blade, means for moving the piece of work past the blade in a direction at a right angle thereto, and means associated with one of the work supporting members for spreading the work in a direction transverse to its direction of movement so that the work spread laterally at the same time that is being stretched.

7. In a machine for stretching hides, skins, eather and other similar pieces wopair of work supporting members spaced from each other, a bladed member arranged to project into the space between the work supporting members, means for causing relative movement between the work supportin g members and the bladed member to fold the work around the edge of the bladed member and into the space between the work supporting members, means for pulling the work over the edge of the bladed member, and means for spreading the work in a direction transverse to this direction of movement so as to maintain approximately die normal width of the piece of work while it is bein stretched.

8. In a machine for stretching hides, skins, leather and other similar pieces of work spaced work engaging members, means for causing relative approaching movement of certain of the work engaging members to cause the work to be folded around an edge portion of one of the members, and means for pulling the work past the spaced members to stretch it, one of the work engaging members having a curved surface provided with helically arranged ribs for spreading the piece of work in lateral directions while it is being subjected to stretching operations.

9-. In a machine for stretching hides, skins, leather and other similar pieces of work, means comprising apair of work engaging members in spaced relation to each other for stretching a piece of work, one of the work engaging members having a curved surface provided with helically arranged ribs er:- tending in opposite directions from points adjacent to the middle portion of the member, and means for pulling the piece of work through the stretching means and over the helically ribbed member so that the piece of work is spread from side to side at the same time that it is stretched in a direction from end to end.

10. In a machine for stretching hides. skins, leather and other similar pieces of work, a pair of work supporting members, a bladed member, means for causing relative approaching movement of the bladed member and the work supporting members to cause the work to be folded around the edge of the bladed member, and means for pull ing the work past the edge of the blade, one of the work supporting member having a curved surface provided with helica -l; ar-

ranged ribs for spreading the piece of work in lateral directions while it is being subjected to stretching operations along lines extending at right angles to the direction of the spreading of the work.

11. In a machine for stretching hides, skins, leather and other similar pieces of work, a bladed member, a pair of work supporting members in spaced relation to each other, one of the work supporting members having a curved surface provided with helically arranged ribs extending in opposite directions from points adjacent to the middle portion of the member, means for causing relative movement between the bladed member and the work supporting members to fold a piece of work around the edge of the blade, and means for pulling the piece of work past the blade and over the helically ribbed member so that the piece of work is spread from side to side at the same time that it is stretched in a direction from end to end.

12. In a machine for stretching hides, skins, leather and other similar pieces of work, means for releasably engaging a piece of work, and means comprising an apron limited in length when compared with the work, for detachably engaging with the Work to pull it past the work engaging means to eifect stretching operations on the work.

13. In a machine for stretching hides, skins, leather and other similar pieces of work, a bladed member, a pair of spaced members for co-operation with the bladed member in stretching the work, means for causing relative movement between the bladed member and the pair of members to fold a piece of Work around the edge of the bladed member, and means comprising an apron for detachably engaging with the work for pulling it past the bladed member to effect stretching operations on the work.

14. In a machine for stretching hides, skins, leather and other similar pieces of work, means for releasably engaging a piece of work, an apron of limited length for engaging with a portion only of the work, and means for winding the apron and the engaged portion of the work in a roll whereby other portions of the work are pulled past the work engaging means to effect stretching thereof.

15. In a machine for stretching hides, skins, leather and other similar pieces of Work, a bladed member, a pair of members spaced with respect to each other, means for moving the bladed member and the pair of members relatively to each other to cause the work to be folded around the edge of the bladed member, an apron for engaging with a portion of the work, and means for winding the apron and the engaged portion of the work in a. roll whereby other portions of the Work are pulled over the edge of the bladed member.

16. In a machine for stretching hides, skins,

leather and other similar pieces of work, a bladed member, a pair of spaced members, means for causing relative approaching movement between the bladed member and the spaced members to efiect folding of the work over the edge of the bladed member, and means for moving the work past the edge of the bladed member, said spaced members being adjustable to present different portions of their surfaces for contact with the work.

17. In a machine for stretching hides, skins, leather and other similar pieces of work, means comprising spaced members for stretching a piece of work, one of the spaced members having a curved surface provided with .helically arranged ribs extending in opposite directions from points adjacent to the middle portion of said member and operative to spread the work in directions at right angles to the direction of stretch performed by the stretching means, said ribbed member being rotatably adjustable to present different portions of its surface for operation on the work, and means for moving the piece of work through the stretching means and over the surface of the ribbed member.

18. In a machine for stretching hides, skins, leather and other similar pieces of work, means for releasably engaging opposite surfaces of a piece of work, power means for operating the first-mentioned meansbetween work receiving and work engaging, positions, power means directly under the control of the operator for moving the piece of work past the work engaging means when the latter is in work engaging position, manually operable means for initiating return of the work engaging means to work receiving position, and means for automatically terminating the operation of the work moving means in timedrelation to the return of the work engaging means to work receiving position.

19. Ina machine for stretching hides, skins, leather and other similar pieces of work, power operated means for engaging o eposite surfaces of a piece of work, power operated means for rolling a portion of the piece of work on a roll to pull it past the work engaging means, a manually operable member for initiating operation of said rolling means, and means for automatically terminating the rolling operation in timed relation to the operation of the firstanentioned power operated means.

20. In a machine for stretching hides, skins, leather and other similar pieces of work, means for engaging opposite surfaces of a piece of work, power means for causing operation of the work engaging means in directions toward and from the work, a manually operable member for controlling the power means, power means for pulling the piece of work past the work-engaging means, manually operable means for initiating operation of the last-mentioned power means,

and means for automatically throwing the last-mentioned power means out of operation following an operation of the manually operable member.

21. In a machine for stretching hides, skins, leather and other similar pieces of work, spaced members for engaging opposite surfaces of a piece of work, means for moving certain of the spaced members relatively to each other to effect folding of the piece of work over the edge of one of the members, a roll upon which the piece of Work may be rolled to pull portions thereof past the spaced members to effect stretching operations on said portions, power means for operating the roll, manually operable means for initiating operation of said power means, and means for automatically throwing the power means out of operation.

22. In a machine for stretching hides, skins, leather and other similar pieces of work, spaced members for engaging opposite surfaces of a piece of work, power means for causing relative approaching and separating movements of certain of the spaced members, manually operable means for controlling said power means, a roll, power means for winding portions of the piece of work upon the roll to pull other portions of the work past the spaced members, manually operable means for initiating operation of the lastmentioned power means, and means for automatically terminating the operation of the last-mentioned power means.

23. In a machine for stretching hides, skins, leather, and other similar pieces of Work, a bladed member, two members comprising a roll for co-operation with the bladed member for stretching a piece of work, means for pulling the work past the bladed member, and means comprising a spreader surface on said stretching roll for spreading the work in a direction transverse to the direction of stretching of the work.

In testimony whereof I have signed my name to this specification.

JOSEPH H. HARRISON. 

